1. Field of the Invention
This invention relates to assessing conditions of relays, and more particularly to systems and methods for testing a relay set, such as a switch matrix.
2. Description of the Related Art
A relay is an electrical switch that opens and closes an electrically conductive path under the control of another electrical circuit. Electromagnetic relays are generally susceptible to mechanical or electrical failures that can cause the relay to operate unreliably. For example, a relay maybe stuck in an opened or closed position, often referred to as a relay that is stuck-open or stuck-closed. Products which integrate the use of relays, such as electronic switch modules, are generally susceptible to similar problems. In cases where the relay contacts are exposed to outside signals, as is normally the case in a switch module used with automated test equipment, this problem can be further exacerbated because there is no integrated circuitry to protect the relays without impacting product performance. Accordingly, these types of products are susceptible to failure due to either extended normal operation or abusive operation.
While a relay failure is often an expected circumstance of using these types of products, this occurrence is nonetheless inconvenient. If a relay failure is undetected, the failure can cause errors in operation and function of a corresponding device, such as a switch. In the event of automated test equipment, relay failures can cause mis-routing of signals and invalid test results. Furthermore, due to the often high density of relays in these types of switch modules, isolating a failure once it occurs can be an even larger inconvenience. For example, a user may spend a great deal of time testing operation of individual relays in an attempt to locate a failure, and even after locating the failure a switch module may need to be reconfigured to work around the failure. In some instances, a routine may be executed in software to operate one or more relays to locate a failure. Such routines, however, may not be able to identify or resolve the failure, may be time consuming, and may be physically taxing on the switch and the relays themselves as hundreds of repetitive iterations of cycling relays may be performed in an attempt to isolate a failure to one or more relays.
Accordingly, it is desirable to provide a relay module test system and method to provide for efficient and accurate testing and diagnosis of electronic devices that incorporate relays, such as electronic switch modules.